Footings, piers, grade beams and the like are used in the construction of most building types. Moisture control, drainage, and frost protection along with structural load bearing are the primary concerns of a high performance foundation. Ideally, the foundation works to control infiltrating moisture by simultaneously channeling rain or ‘free’ water downwards and away from the foundation while also halting wicking moisture. Further, the foundation ideally protects against frost and the effects of freezing and thawing soils. Additionally, the foundation should act to reduce infiltration and exfiltration of air and harmful gases from the surrounding soils. In addition, the foundation must be capable of supporting the super-imposed loads of the structure above while resisting the lateral loads imposed by the surrounding soil and the hydrostatic pressures of the water within the soil.
A building's footing assembly is typically constructed of porous concrete components which have a very low thermal resistance. In order to improve the thermal resistance of a footing assembly and to block thermal transfer, insulation is usually installed on the concrete wall, footing and/or grade beam. This insulation becomes part of the overall building envelope and can have major effects on the performance of a building's envelope during its life cycle.
One of the most common methods of insulating the footing assembly is utilizing insulating foams such as those of rigid extruded polystyrene and expanded polystyrene. These rigid foams are generally employed in the form of rectangular panels or boards attached to the foundation walls to provide the necessary thermal break to reduce thermal conductivity. These conventional insulation systems are subject to many variables that can affect their life cycle performance.
The most prominent flaw in current insulation technology is that there are no systems available that allows the footing insulation to be installed directly in-line with or integrated as part of the above grade building envelope. Currently, on typical footings, the entire top face of below grade footings is exposed to thermal conductivity, which allows direct thermal penetration below the wall assemblies causing the interior (typically concrete) floors to conduct exterior temperatures directly into the interior spaces.
Other flaws in the current conventional insulation systems include variations in the sidewalls of the excavated earth in which the conventional insulation is being installed. Due to the inconsistencies caused by common digging techniques, the placement of the current insulation at the face and/or rear of the excavated footing is not uniform. As a result, the rigid insulation bends and breaks because it is forced outward when the concrete is poured. Additionally, current insulation panels are typically installed with standard eight-foot panels that have a square edge that is butted up together with other panels without mechanical fasteners or any ability to be jointed together. This causes these panels to separate and become uneven at the joints which provides additional thermal bridging and allows cold/heat transfer past the building envelope.
Another break in the thermal barrier of below-grade concrete footings is caused by the damage that occurs after the concrete footings and insulations are placed. Much of this damage is caused by the mechanical, electrical and plumbing subcontractors and other trades as they construct their portions of the building project. These subcontractors typically dig down on both sides of the newly placed concrete footing, removing the insulation barrier in order to rough-in the pipes, conduits and other penetrations so that they can have pathways to feed their needed building equipment. They will also drive over these concrete footings and insulation with their heavy construction equipment and thus damage and break the insulation system from above.
Based on the foregoing, there is a need for an improved thermal insulation barrier system that will provide adequate insulation for a grade beam, footing and wall assembly. Such an improved thermal insulation barrier system would provide reliable interlocking of multiple rigid insulation panels. Additionally, it would provide a continuous alignment of rigid panels beneath a building envelope. Further, such an improved thermal insulation barrier system would provide a continuous thermal insulation barrier between rigid panels above in the exterior wall by aligning with the rigid panels below in a grade beam footing. The present invention overcomes prior art shortcomings by accomplishing these critical objectives.